Presser-foot mechanism for shoe-sewing machines.



PATENTED SEPT. l, 1903.

M. T. DENNE. PRESSER FOOT MECHANISM FOR SHOE SEWING MACHINES.

APPLICATION FILED AUG. 9. 1902.

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M. T. DENNE.

PRESSER FOOT MECHANISM FOR SHOE SEWING MACHINES.

APPLICATION FILED AUG. 9. 1902.

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UNITED STATES Patented September 1, 1903. I?

PATENT OFFICE.

PRESSER-FOOT MECHANISM FOR SHOE-SEWING MACHINES.

:1ECIFI(LACLION formingpart of Letters Patent No. 737,716, dated September 1, 1903.

Application filed August 9, 1902. Serial No. 119.147. (No model.)

To (LZZ whmn it may concern:

Be it known that 1, MARK THOMAS DENNE, a subject of the King of Great Britain, residing at 22 Finborongh road, Fulham, London, England, have invented new and useful Improvements in Presser-Foot Mechanism for Shoe-Sewing Machines, of which the following is a specification.

This invention relates to boot and shoe sewing machines of the type described in the specifications of Letters Patent Nos. 505,034.

and 529,064E and to such machines which have an adjust-able presser-foot, and has for its object the improvement of the mechanism for looking or preventing the presser-foot from yielding while the needle is passing through the work and the stitch being formed.

To enable the invention to be fully understood, I will describe the same by reference to the accompanyingdrawings, in which Figure 1 is an elevation of the boot and shoe sewing machine shown and described in the specification of patent application, Serial No. 67,471, filed July 8, 1901, and having my improved mechanism for controlling the presser-foot applied thereto. Fig. 2 is a side elevation of the said mechanism detached. Fig. 3 is a plan thereof; and Fig. 4 is a section on the line 4 4:, Fig. 3. Fig. 5 represents a top plan view of the locking-pawl and showing a portion of the segment. Fig. 6 is an enlarged partial side elevation of the pawl and segment.

a is the framing of the machine, and b the main or cam shaft.

d is the needle, and f the awl, both oscillating about a common center f.

g is the race containing the shuttle, which rotates in a plane at right angles to the needle and awl.

h is the table or support for the work, the said support having in it a slot for the passage of the awlffrom the under side and the needle d from the upper side.

it is the presser-foot or channel-guide arranged to turn about the center f, so that it can be adjusted relatively with the work sup port It, according to the thickness of the work, and its pressure relieved While the work is being fed by the awl.

7L3 is the lever-handle, fulcrumed to the frame at h and connected to the presser-foot through the medium of the lever 72, link 71,

and arm h on the said presser-foot, whereby the latter can be lifted in order to enable the work to be placed in position on the table h.

h is a spring one end of which is connected to the lever h while the other end is connected to the frame a, the said spring serving to cause the presser-foot 712 to bear with pressure upon the work and hold it firmly.

All of the above parts are of known construction.

I will now describe my improvements.

In carrying out my invention I provide the lever-handle h with an extension i, having a segment of rack-teeth t" t", the said extension having its center at the fulcrum h.

2' is a spring-pawl which by engaging the teeth v1 locks the presser-foot, the said pawl sliding in a recess 11 in a lever '5 fnlcrnmed at t and i in the frame a of the machine and in a bracket 71 respectively. For enabling the pressure of the presser-foot on the Work to be relieved while the awl is feeding the work I provide the lever t with a roller 2' held in contact with the periphery of the disk g (which in this machine has a cam-groove for operating the awl) by the spring '11", the said disk having a cam groove or surface 11 in the path of the said roller, so that in the rotation of the said disk g when the said cam groove or surface al comes opposite the roller the latter will becaused to enter it by the spring 1', thereby turning the lever i on its fulcrum and turning the lever h also upon its fulcrum through the medium of the pawl 1L and extension 2' and through the medium of the connections If h it slightly lifting the presser-foot 71 For unlocking the presserfoot when it is required to place the work on the work-table and to allow of the automatic adjustment of the presserfoot to various thicknesses of stock I arrange that the pawl shall be withdrawn from the part 11 of the lever it and for this purpose I form a cam or raised surface j upon the disk 9, and I fulcrum to the bracket 6 a leverj, carrying at one end a rollerj designed to be held against the disk g in the path of the cam-surfacej by means of a springj connected at one end to an extension on the said lever, while the other end is connected to the bracket i The other end of the lever 7" is provided with a pinj, which extends through a holej Fig. 2, in the bracket 71 and bears against a crank arm 7' fulcrumed to the bracket t the upper end of the said arm 7' engaging a recess j in the pawl F. The part of the pin 3" which bears against the armj is preferably formed eccentric to the main part, (which is screwed'into the leverj,) so that it can be adjusted relatively with the said arm by rotating it. By the described arrangement when the cam-surfacej comes into contact with the roller j the pinj is caused to press against the arm 7' and forces back the pawl out of engagement with the teeth 71 of the part 1' of the lever h so that the latter can be moved to lift the presserfoot 72?. The pawl i is advantageously formed of a series of bars laid side by side in the recess i each of the said bars having a recess 9' at its rear end for the reception ofa spring j one end of which bears against the end-of the recess j, while the other end bears against a plate j", fixed to the lever 'i by a screwj In the drawings the pawl is shown as consisting of four bars, as indicated in Fig. 4 by the dotted lines. By constructing the pawl in parts or sections, as described, the points of each part can be more easilyground when removed from the recess i than if the pawl were formed of one piece. The points of the various sections of the pawl can be so disposed one with the other, as shown in an exaggerated manner in Fig. 6, as to give a fine adjustment with a coarse pitch of teeth in the segment-rack. Thus if the pitch of the segment-teeth is sixteen to the inch and there are four pawls the 'points of which are set one sixty-fourth of an inch apart then the segment can be locked at intervals of one sixty-fourth of an inch, while a strong tooth is used of one-sixteenth of an inch pitch on the segment.

j is a cam projection similar to the projection j and which I advantageously employ for operating the leverj to move the pawl i to release the presser-foot just before the awl leaves the work after it has done feeding the same.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. In a sewing-machine, the combination with the needle, awl and shuttle, and a worksupporting table, of a pivoted presser-foot, a spring-operated hand-lever connected thereto and provided with a ratchet-segment, a pivoted locking-frame, a longitudinally-movable pawl carried by said'frame and engaging said segment, to lock the presser-foot in operative position, and a cam for rocking said lockingframe on its pivotal supports to lift said presser-foot while the work is being fed, substantially as described.

2. In a sewing-machine, the combination with the needle, awl and shuttle, and a worksnpporting table, of a pivoted presser-foot, a spring-operated hand-lever connected thereto and provided with a ratchet-segment, a pivoted locking-frame, a longitudinally-movable pawl carried by said frame, and engaging said segment, to lock the presser-foot in operative position, a cam for rocking said locking-frame on its pivotal supports to lift said resser-foot while the work is being fed, and mechanism for retracting said pawl longitudinally to dis engage said pawl from said segment to release the pawl after the feeding movement, substantially as described.

3. In a sewing-machine, the combination with the needle, awl and shuttle, and a worksupporting table, of a pivoted presser-foot, a spring-operated hand-lever connected thereto and provided with a ratchet-segment, a pivoted locking-frame, a longitudinally-movable pawl carried by said frame and engaging said segment, to lock the presser-foot in operative position, a spring engaging said pawl and forcing it into engagement with said segment, a part connected with said locking frame provided with a friction-roll, a cam engaging said roll for rocking said frame and lifting said presser-foot while the work is being fed, mechanism for retracting said pawl including an arm provided with a friction-roll and a camengaging said arm for retracting said pawl longitudinally to release the segment and presser-foot at the conclusion of the feeding movement, substantially as described.

4. In a sewing-machine, the combination with the needle, awl and shuttle, and a worksupporting table, of a pivoted presser-foot, a spring-operated hand-lever connected thereto and provided with a ratchet-segment, a pivoted locking-frame a plurality of longitudinally-movable pawls carried by said frame and havingtheir points out of line with each other, an independent spring for each pawl for holding them in engagement with the seg ment, an arm connected'with said lockingframe, and provided with a friction-roll, a cam engaging said roll to rock said frame and lift said presser-foot, a lever engaging all of said pawls, mechanism for operating said lever including an' arm provided with a friction-roll, and a cam engaging said roll for withdrawing all of said pawls simultaneously, substantially as described.

I MARK THOMAS DENNE. Witnesses:

H. NIXON, ROBERT FORREST. 

